Quinoenzymes represent a widely distributed class of oxidoreductases with quinone cofactors that frequently occur in conjunction with metal ions as part of the catalytically functional redox active complex. Metal-quinone interactions have also been implicated in the mechanism of action of pharmacologic agents, including antitumor active antibiotics. The proposed project aims at structural characterization and mechanistic elucidation of synthetic quinone-metal complexes designed as bioorganic models to provide fundamental chemical precedents crucial for understanding the mechanism of action of biologically active metal-quinone complexes. Through the use of optical absorption spectroscopy, 1H- and 13C-NMR techniques as well as ESR methods the structural properties of the complexes will be delineated. Their redox chemistry will be developed using electrochemical methods as well as chemical reducing and oxidizing agents. The structural and chemical properties of the semiquinone radicals and their metal complexes will be elucidated using ESR spectroscopy in combination with electrochemical and kinetic studies. The methods developed in the project should provide useful precedents and may become applicable for studying metal-ligand interactions in other redox active heterocyclic systems of biological importance. The proposed project aims at providing research training to introduce minority students to biochemical research. The students will gain hands-on knowledge in modern techniques of organic synthesis, reaction kinetics, electrochemistry, ESR (including computer simulation of spectra), as well as routine analysis techniques such as FT-NMR, FT-IR and HPLC. Significantly, the students will be involved not only in the technical aspects of the proposed research but will also participate in the design of the experiments, interpretation of the results, will be expected to give scientific presentations and contribute to the writing of manuscripts for publication.